The greatest problem with these sensors is electrolysis and subsequent oxidation, due to the DC current flowing through the sensor in a humid environment.
There are some solutions: Most of the circuits that supposedly feed the sensor with A are bogus as it is apulsed DC at best..
One could try a capacitive sensor...... in theory very good but in practice plagued by issues.

What I have done is to remove constant current from the sensor by feeding it from a transistor that I can switch on and off. I take a measurement every 2-6 hrs and switch the current off in between. Makes a huge difference

@jpaulin Looking good. And I mean GOOD

@scalz A very late reply, but someone else might be helped with it.
Hardware SPI is working.
The onnly thing is that on W5100 shield it will work without any problem but with most 5100 modules you need a small modification fixing w5100 problems